If it wasn't about the amazing MotionScan faces it was the narrative qualities, the rich recreation of 1940s LA or the odd combination of a modern Rockstar title and classic point-and-click adventure mechanics.
Was it everyone's cup of joe? Not at all, but it was a title that got people talking and it will be a reference point in gaming for years to come.
Forget your countdown clocks, your ten second trailers and your mysterious solitary screenshots, the biggest tease in video game history was Portal.
Chucked onto The Orange Box by Valve in a very by the way sort of manner, the short, sharp puzzler became an overnight cult sensation which soon started to spread to the masses as well.
Witty, innovative and atmospheric are probably the three best adjectives for the Portal world, although there are many more. The point is when Valve came to making a full-fat Portalling experience with the sequel it didn't disappoint.
Portal 2 is every bit as imaginative, inventive, hilarious and heart-warming as its predecessor and then some. A true and rare gem in the world of gaming.